[rcentros]

My eyes have trouble with the front-lit readers (I guess it's the light layer), which is why I'm pretty much stuck with "old tech."

Kindle Keyboards and the Kindle "no-touch" 4th and 5th generations can usually be found pretty cheaply and they have sharp screens (for 167ppi) – but you're stuck with a basic font (which I, personally, don't mind). The original Kindle Touch and the 7th and 8th generation Kindle Basics can also be found pretty cheaply, but I never thought their fonts were as sharp and dark as the Keyboard or the "No Touches" – though, with the original Kindle Touch, you could add fonts via a simple hack, which helps.

I think the best font rendering available (in old tech) was done by the Sony x50 series (350, 650, 950) and T1, T2 (and, probably, the T3). The T3 has the highest resolution of all of these, but they're pretty expensive for old tech and (usually) used and I've never personally seen one. The T2 has a sharp, "whiteish" screen, probably the best screen I have. I embed Constantia via Calibre (you pretty much have to embed fonts with Sonys if you like dark fonts). The 350, 650 and 950 are not far behind. The T1 has a good screen but they had some issues with the dictionary that, as far as I can tell, never got resolved. Both the Sonys and Kindles (mentioned above) use the Oxford dictionaries. (Sonys are rarer and more expensive, but 350s are often available on eBay.)

The Nook Simple Touch (without Glowlight) had a clear, sharp screen – but the fonts aren't rendered quite as well as the Sonys. Even the original Kobo Wireless has good, sharp fonts, if you embed your fonts via Calibre.

If you're looking for a new reader, an inexpensive one without a front light is the InkBook Classic 2 which, until recently (?) was available on Amazon for $80. (I can't personally vouch for this one.)